That works really well. And yes, slippi.g sheets partially under the thing is very handy.
In my case, I used the kitchen flatscreen TV as an RPG countertop. 😎
Lay it flat on the table, connect in to my (the GM) laptop and open a browser with FoundryVTT fullscreen on it.
Voilá: dynamic battlemap where you can place real figures on .
Works surprisingly well.